/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* $Id: MainReference.java,v 1.1 2007/04/12 06:41:18 cvsuser Exp $ */

package com.wisii.wisedoc.area;

import java.util.Iterator;
import java.util.List;

/**
 * The main-reference-area generated by an fo:region-body This object holds one
 * or more span-reference-areas (block-areas stacked in the block progression
 * direction) See fo:region-body definition in the XSL Rec for more information.
 */
public class MainReference extends Area {

	private BodyRegion parent;
	private List<Span> spanAreas = new java.util.ArrayList<Span>();
	private boolean isEmpty = true;

	/**
	 * Constructor
	 * 
	 * @param parent
	 *            the body region this reference area is placed in.
	 */
	public MainReference(BodyRegion parent) {
		this.parent = parent;
		addTrait(Trait.IS_REFERENCE_AREA, Boolean.TRUE);
		/* 【添加：START】 by 李晓光 2008-11-13 */
		setAreaKind(AreaKind.REFERENCE);
		/* 【添加：START】 by 李晓光 2008-11-13 */
	}

	/**
	 * Add a span area to this area.
	 * 
	 * @param spanAll
	 *            whether to make a single-column span
	 * @return the created span area.
	 */
	public Span createSpan(boolean spanAll) {
		if (spanAreas.size() > 0 && getCurrentSpan().isEmpty()) {
			// Remove the current one if it is empty
			spanAreas.remove(spanAreas.size() - 1);
		}
		RegionViewport rv = parent.getRegionViewport();
		int ipdWidth = (int) parent.getIPD()
				- rv.getBorderAndPaddingWidthStart()
				- rv.getBorderAndPaddingWidthEnd();

		Span newSpan = new Span(((spanAll) ? 1 : getColumnCount()),
				getColumnGap(), ipdWidth);
		/* 【添加：START】 by 李晓光 2008-10-6 */
		newSpan.setParentArea(this);
		/* 【添加：END】 by 李晓光 2008-10-6 */
		spanAreas.add(newSpan);
		return getCurrentSpan();
	}

	/**
	 * Get the span areas from this area.
	 * 
	 * @return the list of span areas
	 */
	public List<Span> getSpans() {
		return spanAreas;
	}

	/**
	 * Get the span area currently being filled (i.e., the last span created).
	 * 
	 * @return the active span.
	 */
	public Span getCurrentSpan() {
		return (Span) spanAreas.get(spanAreas.size() - 1);
	}

	/**
	 * Indicates whether any child areas have been added to this reference area.
	 * 
	 * This is achieved by looping through each span.
	 * 
	 * @return true if no child areas have been added yet.
	 */
	public boolean isEmpty() {
		if (isEmpty) {
			boolean nonEmptyFound = false;
			if (spanAreas != null) {
				for (Iterator spaniter = spanAreas.iterator(); spaniter
						.hasNext();) {
					Span spanArea = (Span) spaniter.next();
					nonEmptyFound |= !spanArea.isEmpty();
				}
			}

			isEmpty = !nonEmptyFound;
		}
		return isEmpty;
	}

	/** @return the number of columns */
	public int getColumnCount() {
		return parent.getColumnCount();
	}

	/** @return the column gap in millipoints */
	public int getColumnGap() {
		return parent.getColumnGap();
	}

	/* 【添加：START】 by 李晓光 2008-10-20 */
	public List getChildAreas() {
		return spanAreas;
	}
	/* 【添加：END】 by 李晓光 2008-10-20 */
}
